GC-Recomposition-Olfactometry (GC-R) and multivariate study of three terpenoid compounds in the aroma profile of Angostura bitters

Abstract

Foods and beverage aroma results from multicomponent mixtures of volatile compounds present in the food that interact with olfactory receptors and produce a perceptual response in the brain. However, the perceptual interactions that occur when complex odor mixtures are combined are not well understood. Here we used Gas chromatography-Recomposition-Olfactometry (GC-R) to better understand the role that individual compounds have on the perceived sensory aroma of bitters. Bitters are the concentrated alcoholic extract of flavorful plant materials with a wide range of complex sensory and chemical aroma profiles that have not been extensively studied. Previously, we demonstrated that Angostura bitters are characterized by complex aroma attributes described as cola , ginger , orange peel , and black pepper and that the volatile composition of Angostura bitters is predominantly composed of terpenoids. Using GC-R to create in-instrument mixtures of the Angostura headspace extracts, the sensory attributes of Angostura extracts with linalool, α-terpinyl-acetate and caryophyllene omitted were evaluated. The omission experiments demonstrated direct and indirect effects of the individual compounds on the aroma attributes of Angostura bitters, through masking, additive, and synergistic interactions. Caryophyllene in particular, which was present in the headspace extracts at concentration only slightly above sensory threshold levels, had a large and unexpected impact on the sensory properties of the mixtures and may be most responsible for the aromas associated with the whole sample. The GC-R and statistical approaches used here provided valuable tools to reveal relationships among individual compounds and aroma attributes of foods that have not been currently theorized using existing analytical approaches.

Odor Perception Interactions between Free Monoterpene Isomers and Wine Composition of Pinot Gris Wines

“…Linalool has been found to mask aromas when in combination with other terpenes. 42 Perception of monoterpenes in matrix 3 are closest to what can be expected in wines, as it is very similar with both nonvolatile and volatile compositions.…”

“…Linalool also appeared to mask the perception of compounds found in profile 4 as this was the main difference between monoterpenes in profile 3 versus profile 4. Linalool has been found to mask aromas when in combination with other terpenes . Perception of monoterpenes in matrix 3 are closest to what can be expected in wines, as it is very similar with both nonvolatile and volatile compositions.…”

Strategies for the identification and sensory evaluation of volatile constituents in wine

“…It has been suggested that GC-R-O is capable of the in-instrument perceptually analysis of compounds occurring in the sample, even if they are below their odor threshold, instrumentally undetectable, or without reference standards (Johnson et al, 2012). However, GC-R-O has been applied only in studies of perceptual interactions (Johnson et al, 2012(Johnson et al, , 2019 but not yet demonstrated its potential for identifying unknown volatile components. may also be considered for the purpose of identification, although these techniques have been more focused on perceptual interactions during postidentification.…”

“…Subsequent GC-MS analysis on these fractions may potentially reveal new candidate volatile compounds that have an indirect aroma impact. Another method for performing perceptual interaction studies is to use GC recomposition-olfactometry (GC-R-O) (Johnson et al, 2012(Johnson et al, , 2019. As indicated by its name, this technique enables the highly automated fractionation (through GC separation and Deans switch), recombination (cryogenic trapping of selected volatiles), and sensory evaluation (olfactometry) in one instrument (Figure 13b).…”

Free and Bound Volatile Aroma Compounds of ´Maraština´ Grapes as Influenced by Dehydration Techniques

“…Monoterpenes were found to influence fruity aromas (orange flowers) in wine, suggesting that linalool (odor threshold of 6 µg/L) [34] and linalool oxide may interact with non-volatiles, resulting in change in their aroma perception [33,35].…”